1. Field of the Invention
The present invention relates to a stop assembly and, more particularly, to a stop assembly for use with a cart for sheet material and, most particularly, to a stop assembly for use with a cart for sheet material that readily extends and retracts, and yet is unobtrusive in a storage position.
2. Background Information
Hand carts or motorized carts are routinely employed for transporting sheet materials, including paneling, drywall, doors, tables, etc. Such a cart usually includes one side that extends upwardly from the base of the cart to support the sheet material. There must be some type of stop on the opposite side of the cart to prevent the sheet material from sliding off that side of the cart. Any permanent stop must be worked around when loading and unloading the sheet material from the cart. Various sized loads must also be accommodated by the stop. Several devices concerned with carts for transporting planar sheet material have been granted patents, including the following.
Burg, in U.S. Pat. No. 2,466,149, describes a stock pickup and carrier truck for handling sheets of material. The four-wheeled truck includes several metal legs with lip ends that extend from the truck to pick up and hold stacks of sheet material.
In U.S. Pat. No. 3,417,877, Corley discloses a movable cart for handling a substantially flat structural member. The mounting structure for supporting the member includes a universal pivot joint that permits the mounting structure to be moved about the pivot between the horizontal and vertical planes, through an angle of at least 90 degrees, and rotated in a horizontal plane, through an angle of at least 180 degrees. Movable stops connected to the cart frame are adjusted so that when the mounting structure is against the stops in the vertical position, the structural member is aligned in the vertical plane. Spacers index the cart with respect to a vertical surface for setting the structural member into position.
Hershberger, in U.S. Pat. No. 5,037,117, describes a caddie for stacking, storing and transporting folding leg tables. The dollies are on casters and are simply constructed with a base and riser member. Locking bars, extending from the risers of each dolly, engage the edges of the first table to be stacked on the caddie. The dollies fold flat for storage. Note, in particular, the edge supports that hold the tables on the cart.
In U.S. Pat. No. 5,042,222, Guthrie discloses a drywall slide board. The drywall slideboard consists of upper and lower hinge plates separated by a horizontal hinge. The upper hinge plate supports a removable top plate, which in turn supports a slide plate of a relatively low friction coefficient material. The lower hinge plate is supported by retaining members, which permit the drywall slideboard to be temporarily installed upon a section of lumber stock, such as a two-by-four for use. Alternatively, the top plate and slide plate may be easily removed from the remainder of the slideboard. Methods of use are further described in which the drywall slideboard may be installed over a two-by-four or similar material at a window opening and used to facilitate the transfer of building materials into or out of the structure. Alternatively, the drywall slideboard may be used to transfer materials up or down a stairway when only the top plate and slide plate are used.
Young, in U.S. Pat. No. 5,460,469, describes a panel lifting apparatus having a U-shaped horizontal frame with rollers mounted along the bottom for transporting the frame from place to place. A pair of inclined channels is mounted in spaced relation along the apex of the frame. A pair of hooks having rod like extensions are each mounted on a frame having rollers for rolling along the inclined channels to roll the hooks upward and downward along the inclined channels. A crank and drum are rotatably mounted on one of said channels. A cable has its ends attached to the pair of hooks and an intermediate portion extending through the drum. Rotation of the drum by the crank in one direction causes the cables to wind in opposite directions on the same drum to wind the ends of the cables upward, simultaneously, and thereby draw the hooks upward on the channels, simultaneously. The channels extend sufficiently downward to be adjacent the frame rollers and the ground that the hooks may be lowered by the crank to immediate adjacency to the ground and to receive a drywall panel thereon adjacent the ground. The hooks may lift the panel up to a height where they may be transferred onto a panel lifter having an extended height capability.
In U.S. Pat. No. 5,584,399, King discloses a unique framing system, which provides efficient use of floor space for storing panel members in any one of several desired configurations. The several interactive components of the system interfit easily, such that the system may be tailored into a variety of configurations to suit a particular application. Wheel assemblies may be mounted at each end of the frame assembly and are also configured for easy application and removal. Note, in particular, FIG. 10.
Young, in U.S. Pat. No. 6,032,966, describes a bulk drywall rolling support device. The device has a near horizontal frame, with its forward end inclined upward in relation to its rearward end. The frame has a pair of beams on each side with a lateral bar fixed between the beams. A pair of upward extending sleeves is mounted on the outside of each beam. A pair of rods is adapted to be slidably inserted into the sleeves and extend upward and slightly rearward therefrom. The device has four wheels mounted at the corners of the device. Each rod has a handle near its upper portion for grasping by an operator for rolling the support device about on its wheels. The device is adapted to receive drywall panels, with the lower edge of the panels resting onto forward and upward inclined beams, and the rear sides of the panels resting against the rods. The device has storage ledges for storing the rods when not in use and a mechanism to lock the rods in their storage position so that the handle on one of the rods may be used to lift the rod and the device.
In U.S. Pat. No. 6,786,503, Young discloses a panel carrying cart, having an elongated overall frame formed of a pair of elongated frame sections pivotally mounted about a horizontal axis at their inner ends. The frame sections are each formed of a pair of parallel rods and upright end frames. A plurality of lateral frame rods is adjustably mounted along the length of the parallel rods of the front and rear frames so that the lateral rods may be moved to different locations to better accommodate loads carried on the lateral rods of the cart. A pair of L-shaped lateral rods each has one end mounted in the lateral rods, with their other ends extending upward to hold panels or other objects on the lateral frames on the cart. Wheels are mounted to the front and rear frames for moving the cart about to different locations with panels or other object thereon.
Muscat, in U.S. Pat. No. 6,866,274, describes an article transport dolly for transporting sheets of drywall, glass and the like from one site location to another. The article transport dolly includes an article carrier member, including a base having a top surface upon which articles can be carried. A non-slip mat member is disposed upon the top surface of the base to prevent articles from sliding thereupon. A spring plate comprises a sheet of rigid material upon which the article carrier member is mounted. A carrying handle/stand is attached to the article carrier member for standing the article carrier member upon a ground and for carrying the article carrier member. A wheel assembly includes an axle upon which the spring plate is securely mounted. A brake assembly includes brakes mounted to the article carrier member for braking the wheel assembly.
Applicants have devised a retractable stop assembly for attachment to a cart for sheet material that is highly versatile and stores in an unobtrusive position.